I took my recently purchased (not new) T-28 Ultra Micro out for a few flights before work this morning. After a crash which knocked the battery free of the plane, I plugged the battery back in and now the motor rus at full speed. Moving the throttle stick on the transmitter has no effect. The other controls (rudder, etc)still respond to the transmitter sticks. Turning off the transmitter has no effect. Motor rus at full until I disconnect the battery.

I really didn't think the crash was hard enough to break anything.

Has anyone ever seen this problem? Do you think I have a bad receiver/esc?

Thanks.

When I connected the motor to wrong port (+ and signal i/o + and -) it also give me full speed when I connected the battery. You may try to disconnect the motor and reconnect it or check the connector.

Two additional things:

The throttle axis may be reversed (happened to me). The 6400 brick may have been programmed from brushed to brushless control.

Could be a burned FET on the motor controller, I've seen the same with Plantraco.

What is an FET?

It is the output transistor that is used to turn the motor on and off, they usually fail by burning up and cracking the plastic case on the component so a visual check is normally all that is needed. Look for a small burned up chip on the receiver board.

Thanks guys. The problem is now fixed. The brick must hae swithed to brushless control during the crash. I followed the procedure in the AR6400 manual to switch it to brushed control.

Thanks for the help.

Ron L. from Southeastern PA

I was just reading this post, sometimes after Ive been over zealous with my UM T-28 and hit the ground a bit harder than normal, I find that the Motor wont work or if it does its stuck on full.... I found out that if I re-bind the bird she comes back to normal....